Apparatus for heating articles



Aug. 1, 1933. H. FRlscHKoRN APPARATUS FOR HEATING ARTICLES Filed Dec. 30, A1931 e Patented Aug. 1, y193.3A l

"i APPARATUS FORJ'HEATINKG ARTICLES Heinrich Frischkorn, Gelsenkirchen, Germany, v

assignor, by mesnev assignments, to The Kopv pers Company of Delaware, Pittsburgh, YPa., af

v Corporation of Delaware Applicationecember so, 1931, serial. No; 583,858, u and in Germany January 2, 1931 e 7 claims. (Cl. 263-9) This invention relates to apparatus for heating mechanical elements, especially of metal and more particularly to apparatus adapted tofpermit theheatingof only parts yoisruch articles..

In' machining certain instance y as twist drills,

metal articlessuch for rock drills and-similar tools, it is frequently'necessary for the purpose ofresharpening or other treatment `temporarily to change the article by heating only parts thereof, for instance at thefpointwhich is exposed to particularlyhard. wear,` into a condition in which it is possible to mould or shape the article.

This is particularly the case vwhen dealing with articles composed of steel.

This heating of the ar ticle lmust be so Vcarried out in the cases mentioned that only a definite part of the article is broughtto the high temperature at which it changesY hardness, whilst the other zonesy of the article into'a condition of less must remain below this temperature. Afurther example in which such heating 'is necessary is the machining of so-called coal cutting picks, in

which it is essential-to avoid heating'the shaft of the pick, as otherwise, owing Vto the'scales which form during the 01T, this shaft would n0 the jaw of the spindle of heating and then flake longer lit accurately in the cutting machine.

One object of my present invention is to provide improvementsv in apparatus for heating workpieces, especially those composed of metals,

which will enable a defin ite section'of the article' to be heated to a high temperature while'avoiding any undesired heating of the other parts of the article, and in which `the zone betweenthe section of higher temperature and the section of lower temperature of they workpiece `is kept eX- traordinarily small.

According to my article under treatment with means for heating vpresent invention I heat .the

in a chamber provided the part of the article which is inserted in the chamber, Vthe said means functioning `for instance eitherfelectrically or with gas. 'I provide this heating chamberfwith'one or more openings for inserting the part ofthe article which is to be heated, androutside the chamber near these openings I provide means for bringing a cooling medium into contactiwith the part 'of the tool not insertedin thev chamber.

`It is preferred in my invention to employ cold air as the cooling medium, and this is blown into a ue in the wall of the oven chamber which is open upwardly and overfwhose upper opening the part ofthe article'which is to be cooled lies when the article is ins articles such as rods to be heated in the middle.

composedof easily oxidisingv metals.

erted into` the `heating "drawing in which:-

.. chamber of the oven.

It isalso possible according toi my invention to provide openings on two opposite sides of the l heating chamber and to supply the cooling medi-r` um v'outside the chamber near each opening. This embodiment -of my invention l permits lengthy vopening which corresponds to the length of the part ofthe workpiece .which is to -b'e heated. Thus, 75 the'workpiece cannot be inserted further into the oven than corresponds tothe temporary position of the slide.` The final object or my invention is to provide an improved method of heating .the oven chamberl in order substantially vtoyavoid burning away the workpieces. n s i For this purpose accordingto my present invention I heat the oven chamber by means of a brick jet burner which `I arrange in the bottom of the chamber in sucha manner that the gases escaping from it do not meetthe workpiece 4directly. f

' By the 'expression brick jet burners one generally understands gasburnersof thetype in which the combustion of Vgas and air takes place inside4 a refractory brick which is provided with a series of narrow flues or channels for this purpose. Inthese flueslor channels they gas and air are practically entirely consumed, so `thatf Y practically no flames *emerge` from the brick.:

In brick jet burners of this type the Vheat is transmitted to the workpiecev on'fthe one hand by the hot wastefgasesV escaping from the burner channels and on'the other hand by radiation ofthe brick whichl becomes heated to a very high temperature. Owing to |the fact thatthe gas and air burn up almost'flam'elessly, the brick jet e burner Yis particularly suited for heating articles With these and Yother objects'of/ my invention in view,'I will now describe the lnature of the present inventiononthe lines of the accompanying Figureql vis, an endelevation of an apparatus constructed in accordance with the invention, one of the' side walls being partly broken away and,

Figure 2 is a vertical longitudinal section along the line 2-2 of vFigure 1.

Figure 3 illustratesy a'modied form or the in- Vvention.

' tory brickwork and resting vona stand 2, oven` to bey heated inserted. Forinserting the larticles a slot 4 is provided inl theupper part ofV the chamber wall on whose Ylevel a series of open,-

lto

Figure 4 illustrates thel brick jet burner on a larger :scale l In the construction or the invention illustrated in Figs.` 1 and 2, in a housing 1 lined with refracchambers 3 are provided intok which the articies ings 5 are provided inthe hcusingl, correspond-l ing to the number of work-pieces illustrated at in Fig. 1, through which the workpieces 6 can be nsertedffrom outside into the oven chambers.

The supporting surface for theworkf-piece V6 `on4 the refractory brickwork `of the liningY of the housing 1 is formed or two `bricks 7 and 8,' the 3 brick 8 serving atthe same time asone wall of the oven chamber v3. The bricks 7 and 8 Vleave between theman upwardly openi'iue or channel 9, at thebottom of which a perforated pipe 10 or 10a isdisposed.V The pipes 10 or 10d serve to introduce cold air yintoV the flue 9, and -for this purpose are :connected'outside with the cold air supply. pipe 13 bymeans ofy pipes llfor 11a controlledfby valves 12. The 'cold air introduced into the flue 9 ows past the part of the element 5 lying across the mouth of the flue and escapes through the Vwaste` gas flue v14 provided in the refractory lining and thence into'a chimney 15.v VAs shown in. Fig, 2v of the drawing the brick 8 is preferably of approximately triangular crosssection so that `the surface 15 for. supporting the workpiece `isas narrow aspossible. The narrower this supporting surface is, the smaller is the zone between the part of the workpiece terial in which aseries of channels 21 broadening f conically towards the oven chamber are provided. Into eachV of the .channels 21 a. nozzle 22 projects from outside which issues from a chamber wrIO . the pipe 24.

into the chamber 23 throughV the pipe 26, the said 23' to which compressed air isv supplied through The combustion gas is introduced chamber 23 being connected with the channels 21 as shown in the drawing.

In theconstruction of brick jet burners slfiownV in. Fig. 4 the `combustion gas is sucked up Vby compressed air Vinto the burner channels 21. v'iously however it is also pcssible to introduce the gas under high pressure and suck up the combustion air by means of the gas.

rlIhe mixture of gas and air introduced into the channels V21 of .the brick 20 is .burned practically completely in" these channels, that is to say, without a name emerging from the burner brick during operation. This property renders the brick Vjet burner particularly suitable inthepresent case, as by avoiding name formation the Vdanger 4, In the modification according to Fig.

intervals.A e A. l V I The` invention as hereinabove set forthis emiof the work-piece being covered with scale is' greatly diminished. The heat from the burner. is transmitted to the article being heated onthe one hand by the hot waste gases issuing from the burner andv on the other hand byf the radiation of the brick, which is heat'edduring operation to al very high temperature, in some cases even t0 .White heat. As shown in-Fig. 2, the burner brick is disposed in the lower part of the oven chamber in such a position that the gases issuingtherefrom ydo not meet the work-piece directly,` but are irst diverted byone .of the walls ofthe chamber.Y The gases yescape from the voven 3 through the opening 4 into the chimney 15.' t Opposite the opening 4in the other wall 27 of the oven a slotted opening 28 is provided in which. a'slide 29 is disposed which has a face 30 lying.V

vertical to the line of the opening 4 or the housing, opening 5. -By displacing the slide v29 the face 30 can be brought jto a definite 'distance from theopening 4. The work-piece introduced into theoven through the ,openings 5 Vand 4 then Y strikes with its forward end against the face 30 of kthe slide 29, so that by suitably adjusting the slide 29 it is .possible to` prevent the workpiece being inserted too vfar into the oven, and being heated throughout too great area.

regards the means for introducing and cooling thegwork-piece.; According to Fig. 3 I provide above the approximately triangular vbrick. 8 a

the oven can be closed so muchv that it is just possible to insert the article 5 through the opening. The slide 31 `has an extension 32'whicrh can Fig. 3 illustrateson alarger scale a modificaktion ofV the oven vaccording to Figs. l and 2 as vertically adjustable slide 31, by meansV of which .the opening 4 for introducing the workpiece into 110 besecured by means of vaV setscrew 33 to'an arm A of the housing of the oven. y Y 3, archannel 34-provided in the oven wall above the part of the work-piece which is to be heatedV serves to lead 01T the hot waste gases from the oven. v

The cold air which is introduced through the pipeV 10 to be blown against the workpiece in the same manner as in the construction according to v Figs. 1 and 2 meets a wedge-shaped projection `35 of the slide 31 above the workpiece 6 which divertsthecold air current ydown upon the upper side ofthe work-.piece 6, as indicated by the arthe flue `14'into the chimney.`

The modification according to Fig. 3, offers the advantage in comparison with the construction according to Figs. 1 and 2 that the heating of the work-piece is even more exact than in the `other construction, since the hot gases are pre'y vented by the slide 31 from iiowing alongthe upper side of the workpiece,as may happen in the construction the work-piece must be turned now and then while the oven is in operation, but this may be omitted in the modiiication according to Fig. 3, or is only necessary at much greater t row in Fig. 3. The coldV air then escapes through VVconstruction accordingto Fig. A2. VvInthelatter Q bodied in a particular vform`,.but may be variously embodied within the scope of the claimshereinafter made. Iclaim:

1. Apparatus for heat treatment of a part only of an article comprising: a heat treating chamber provided. with means for heating Var 1,f'article"inserted therein, said chamber' having an article inlet opening for insertion of the part of the article to be heat treated; a channel outside the chamber near said inlet opening and adjacent the supporting point for an article in said inlet opening; cooling medium supply means in said channel; said channel being open outwardlytoward the article supporting .point and being `broadened towards the same from the cooling medium supplymeans therein. e tf l 2. Apparatus for heat treatment. of a part only of anarticle comprising: a heat treating chamber thearticles in the article inlet opening to the heat l treating chamber. l

3. LApparatus for heat treating a part Vonly ofv 'an article comprising: a heattreating chamber means for'heating'an articlein said chamber; said chamber having an article inlet opening for the insertion of a part of an article to be heated; means provided outside the chamber near said opening for bringing' a cooling mediumfinto contact with the part ofthe article not extending intov the chamber; and a slide above the article inlet opening for varying the f ree section of the same,

said slide having a lateral projection by means of which the cooling-medium moved towards the` article is diverted down-to the upper side of the article before being led away.

1 -Apparatus for heat treating Va part only ofi an article comprising: a heat treating chamber;

a gas off-flow flue communicating therewith; means for supplyingheating gas to said chamber;

an article inlet opening to said chamber for inser-V tion of a part of an article tol be treated therein;

and a.I support for `anarticle in saidopeningcomprising awall of said chamber the inner surface` of which is closely adjacent to and substantially in line with the gas off-flow flue, said wall tapering toward thel article inlet opening and forming thereby a narrow supporting edge for articles in said inlet openings, and means `for directing a cooling vmedium alongside the part of saidwall` outsidethe heat treating chamber and in contact with the part-of the article outside the chamber. h and in the direction of said outflow flue.

5. Apparatus for' heat treating a part only :of

' an article comprising: a heat treating chamber;

-ieo

a gas ofl-owilue communicating therewith;-

means for supplying heating gas to said chamber;

an article inlet opening to :said chamber for insertion of a part of an article to be treated therein; and a support for an article in said opening comprising a wall of said chamberthe inner surface Vof which is closely adjacent to and substantially inline with the gas off-flowllue, said wall tapering toward the article inlet opening and forming thereby a narrow supporting edge forV articles inesaid inlet openings`,j,and means for directing a' g cooling' medium alongside the part of said wallA outside the heat treating chamber and in contact withl the part of the article outside thechamber' and. in the direction of said outflow fiue; a slide above the article inlet opening and in-line with the tapered end of the supporting wall and extending into the outflow flue, saidv slide being adapted to rest on the articles when inthe inletopen'ings therefor and form a restricted channel leading intothe olf-flow flue for'restricting gas passing from'the heating chamber to theoutflow flue` t' from flowing over the portions of the article outsidethe inner surface -of the supporting wan f therefor.

6. Apparatus forheat treating a part yonlyof an article comprising: a heat treating chamber;

insertion' of'ca part of an article to be treated `a gas o-flow' flue communicating therewith.;l means Vfor supplying heating gas to said. cham? ber; an article inlet opening to said chamber for l therein; a support for an article insaid openingr` comprising a wall of said chamber Athe inner surtially `in line with the gas off-'flow flue, said wall tapering, toward the article inlet opening and formingthereby a narrow supporting edge' for articles insaid inletopenings, and Ameans for directing a coolingumedium alongside the part of said wall outside Vthe heat treating chamber` and in c ontactfwith the part of the article outi face of which is closely adjacent to and substan- 00h side the chamber yand in the direction of .said out-fV ilowfflue; a slide vabovethe article inlet opening and inline withthe tapered end of the supporting wall and extending into 'the outflow flue, said slide being adapted to rest on thee-articles when inthe inlet openings therefor and form an inner chamber to the. outflow flue from fiowing over Vtheportions ofthe article outside the inner surface of the supportingjwall therefor; Yand Van "restricted channel leading into the off-flow ue i t for restricting` gas passing from the heating .11'5` .i

outer cooling-medium off-flow-channel leading'v into the aforesaid gas out-flow channel from the means for directing a cooling medium thereto.y

l'7. `Apparatl'is for heat treating articlescomvprising: a heat-treating chamber,` a brick jet l opposite endl thereof atthe top of saidfchamber; a-wall vforming the endgof the chamberopburner therefor at one endthereof, agas olf-flow..

flue' communicatingrwithsaidqchamber at the *12'5 f posite the burner, said wall being in line with the off-flow flue and` extending nearly to the top' of `the chamber and to said flue to `provide a restricted passageway from the Achamber to the flue, said outflow flue having an article 'inlet opening for insertion of articles to be heat treated through the aforesaid restricted passageway' and saidV wall being `tapered towards said restricted passageway to forma narrow supporting surface for articles in said article inlet opening; a Vcooling channel alongside the outer side y of said wall below the article inlet opening; and .i

"means inV said channel for directing a cooling medium through thev channel, past the article inlet opening, to thegasoutowilue.

HEINRICH FRISQHKOBN. 

